Widespread Column - Pupilla muscorum
Turbo muscorum, Pupa muscorum, Pupa badia
A small shell, to about 1.7 mm diameter and 3.7 mm in height, subcylindrical (pupiform), surface nearly smooth with fine irregular striae, about 6 to 7 whorls, last half of the final whorl compressed. Shell coloration is brownish (lighter if periostracum is worn off). Aperture is rounded to ovate, typically without teeth (denticles) although sometimes with a small parietal bulge, a somewhat developed columellar tooth, and a small lower palatal tubercle, crest well developed and paler than remainder of shell, sinulus absent, lip whitish, slightly expanded (flared) and thickened inside with a callus. Occurs at some locations in both dextral (coiling to the right from the aperture) and sinistral (coiling to the left from the aperture) forms (Hendricks 2012, Burke 2013). Internal anatomy is described by Pilsbry (1948).
Pupilla are brownish shells with teeth or internal baffles, and possess an external crest behind the aperture (unlike Columella). The palatal lip is not indented, mature shells have 6-9 wholrls, the combination of which separates Pupilla from similar shaped and sized pupiform shells (Verigo). Absence of teeth in aperture distinguish Pupilla muscorum and P. hebes from P. syngenes and P. blandi. Similar to Pupilla hebes but possesses a pale crest and a palatal callus lacking in that species. Occurs in some locations in both dextral (coiling to the right from the aperture) and sinistral (coiling to the left from the aperture) forms.
Native to Eurasia and much of North American; in the west to Arizona and New Mexico (unconfirmed Oregon). In Montana, reported east of the Continental Divide from seven counties: Gallatin, Golden Valley, Jefferson, Park, Stillwater, Sweet Grass, Wibaux. Elevation range is 823 to 2039 m (2700 to 6690 ft). Range and abundance are poorly documented; current status need investigation. May be abundant at some localities; 68 were reported at one Jefferson County site in late June (Hendricks 2012).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Forested sites; canopy species include aspen, Douglas-fir, Engelmann spruce, Rocky Mountain juniper. Found under woody debris, moss, in talus, and leaf litter. Habitat in Montana is poorly described (Hendricks 2012).
- Literature Cited AboveLegend: View Online Publication
- Burke, T. E. 2013. Land snails and slugs of the Pacific Northwest. Corvallis, OR: Oregon State University Press. 344 p.
- Hendricks, P. 2012. A Guide to the Land Snails and Slugs of Montana. A report to the U.S. Forest Service - Region 1. Montana Natural Heritage Program, Helena, MT. vii + 187 pp. plus appendices.
- Pilsbry, H.A. 1948. Land Mollusca of North America (north of Mexico), Volume II Part 2. The Academy of Natural Sciences of Philadelphia Monograph Number 2(2): 521-1113.
- Additional ReferencesLegend: View Online Publication
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- Beetle, D. E. 1961. Mollusca of the Big Horn Mountains. The Nautilus 74:95-102.
- Beetle, D.E. 1997. Recolonization of burned aspen groves by land snails. Yellowstone Science 5 (summer):6-8.
- Beetle, D.E. 1989. Checklist of recent Mollusca of Wyoming, U.S.A. The Great Basin Naturalist 49(4):637-645.
- Berry, S.S. 1916. Notes of Mollusca of central Montana. Nautilus 29:124-128.
- Harris, S.A. 1978. Vertical zonation of land snails in the Iraqi slopes of the Persian Mountains and in the Rocky Mountains of Alberta, Canada. Arctic and Alpine Research 10:457-463.
- Henderson, J. 1933. Mollusca of the Yellowstone Park, Teton Park and Jackson Hole region. Nautilus 47:1-3.
- Nekola, J.C. and B.F. Coles. 2010. Pupillid land snails of eastern North America. American Malacological Bulletin, 28(2):29-57
- Squyer, H. 1894. List of shells from the vicinity of Mingusville, Montana. The Nautilus 8:63-65.
- Additional Sources of Information Related to "Snails / Slugs"